1. Field of the Invention
The invention relates to an overhead crane including a hoist for raising and lowering loads, and more particularly to arrangements for supporting and stabilizing loads lifted by the hoist to an overhead position.
2. Reference to Prior Art
An overhead crane includes a pair of parallel runways, a pair of bridge girders supported on rollers for movement along the runways, and a trolley supported on rollers for movement along the girders. A motor driven hoist is mounted on the trolley to raise and lower loads. The hoist includes a bottom block suspended from the trolley by cables. The block includes a load-carrying hook. A disadvantage associated with a conventional hoist construction is the potential for loads suspended from the trolley by the cables to sway or become unstable when the trolley is moved.
Current safety standards, at least in some crane applications, require the load to be secured directly to the crane, rather than being suspended by the cables, before the crane moves when personnel are below the crane. Heretofore, this has been done by hoisting the load onto hooks spanning the length of the girders. The girders can then be moved back and forth along the runways to reposition the load. However, to move the load from side to side along the girders, it is necessary to carefully lift the load from the hooks and then move the trolley to the desired new position relative to the girders before again placing the load on the hooks.